<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #container {
      display: flex;
      justify-content: space-around;
      align-items: center;
    }
    .color{
      width: 100px;
      height: 100px;
      background-color: black;
      margin: 10px;
      border: 1px solid #000;
      border-radius: 8px;
      box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    }
    .color:nth-child(2) {
      background-color: green;
    }
    .color:nth-child(3) {
      background-color: white;
    }
  </style>
</head>
<body>
  <div id="container">
    <div class="color"></div>
    <div class="color"></div>
    <div class="color"></div>
  </div>
</body>
<script src="popup.js"></script>
</html>